Methods and devices for estimating residual torque between the braked and braking elements of a vehicle

ABSTRACT

Methods and devices for estimating a residual torque between the braked (e.g., brake disk or drum) and braking elements (e.g., support plate or friction block) of a vehicle based on acquired and reference temperatures, where the reference temperature can be calculated using an N-dimensional calculation model with an N-dimensional vector of input variables, and where said N-dimensional calculation model can be an analytical or experimental characterization of the thermal behavior of the brake.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

DESCRIPTION

The application relates to devices and methods for detecting residualbraking torque, e.g., in a vehicle.

SUMMARY

Residual braking torque is the braking torque, often having relativelysmall values, in a vehicle due to the unintended interaction between thebrake pad and the disc while the vehicle is not actually braking.

This condition can be caused by abnormal operation of the brake caliperto maintain a residual contact between the disc and the pad afterbraking.

The persistence of this contact condition, although typically small, canmaintain a nearly constant residual braking torque that has aconsiderable effect on fuel consumption and brake pad wear over the longterm.

EU6 715/2007/EC standards on CO₂ emissions establish significantly morestringent limits on emissions, forcing vehicle manufacturers to seekinnovative solutions to reduce them.

Embodiments described herein are configured to limit, measure, estimate,and/or prevent residual braking torque, e.g., to reduce fuelconsumption, and thus, the resulting emissions of the vehicle.

The present application describes devices and methods that can estimateresidual braking torque in a vehicle due to undesirable interactionsbetween the brake pad and the disc (or drum), e.g., for each brake pad.

Disclosed devices and methods can enable real-time estimates of residualbraking torque.

Disclosed devices and methods enable estimates of residual brakingtorque that can detect the minimum clearance between the brake pads andthe disc, to help reduce brake delays.

Disclosed devices and methods can estimate residual braking torque in amanner compatible with on-board installations and applications.

According to additional disclosed embodiments, devices and methods canestimate residual braking torque in a manner compatible with on-boardinstallations and applications, e.g., connecting a means of connectionand a means of recording to a remotely controlled system.

According to additional embodiments, disclosed devices and methods use amethod to estimate the residual torque between the braking (e.g., brakepad including friction material and/or support plate) and brakedelements (e.g., brake disc or drum) of a vehicle.

According to certain aspects, the method can be implemented in whole orin part by one or more computing devices (e.g., an electronic controlunit of a vehicle comprising one or more computer hardware processors).The method can include. acquiring the temperature value of said brakingelement. The method can further include determining whether this brakeis activated when the temperature value is acquired. The method canfurther include accepting the acquired temperature value if said brakeis not activated at said acquisition time. If the acquired temperaturevalue is accepted, the method can include automatically calculating areference temperature using input from an N-dimensional calculationmodel with an N-dimensional vector of input variables. The N-dimensionalvector of variables can include at least the acquired temperature ofsaid braking element. The N-dimensional calculation model can be ananalytical or experimental characterization of the thermal behavior ofthe brake. The method can include estimating residual torque bycomparing the accepted acquired temperature to the calculated referencetemperature.

Depending on the embodiment, the N-dimensional vector of variables caninclude at a speed of the vehicle, at least an ambient temperature, atleast a time delay between the instant of temperature acquisition andthe last instant in which the brake was activated, or any combination

The braking element can include a braking disc or drum and said brakingelement can includes a wearable block of friction material and a backsupport plate for the friction material block. The temperature of thebraking element can be acquired by at least one temperature sensorconfigured and positioned to detect the temperature of the back supportplate.

The method can include using a temporal acquisition logic to acquire thetemperature of the braking element based on a sampling frequency for atleast one preset time interval. According to further embodiments, themethod can include using a temporal acquisition logic to acquire thetemperature of the braking element based on continuous sampling for atleast one preset time interval starting from an acquisition instantdetermined by an event.

Depending on the embodiment, at least one variable chosen from vehiclespeed, temperature of the braking element, temporal variation of thetemperature of the braking element, or brake pedal status can used todetermine whether said brake is activated at the instant of temperaturevalue acquisition.

According to certain embodiments, the residual torque can be estimatedwith the N-dimensional calculation model and, in addition, with anacquired change in brake temperature over time. According to additionaspects, a device or system for estimating the residual braking torqueof a vehicle can include a braked element that includes a braking discor drum. The device can further

Include a braking element that includes a block of friction material anda back support plate for said friction material block. The device canfurther include at least one temperature sensor configured andpositioned to detect the temperature of said back support plate. Thedevice can further include an electronic control unit (e.g., a computingdevice comprising one or more computer hardware processors) connected tosaid temperature sensor, with said electronic control unit implementingan N-dimensional calculation model that represents an analytical orexperimental characterization of the brake's thermal behavior. Theelectronic control unit (ECU) being programmed (e.g., with software orfirmware stored in a memory of the electronic control unit) to acquirethe temperature value of said back support plate from said temperaturesensor. The ECU can be programmed to determine whether this brake isactivated when the temperature value is acquired. The ECU can beprogrammed to accept the temperature value if said brake is notactivated at said acquisition time. The ECU can be programmed, if thetemperature value is accepted, to automatically calculate a temperaturereference value by providing an N-dimensional vector of variables. TheN-dimensional vector of variables can include at least the acquiredtemperature of said back support plate, as input to said N-dimensionalcalculation model. The ECU can be programmed to estimate residual torqueby comparing the accepted acquired temperature to the calculatedreference temperature.

The temperature sensor can be a contact temperature sensor integratedinto said back support plate. In some embodiments, the temperaturesensor can be a non-contact temperature sensor.

The temperature sensor can be configured and positioned to detect thesurface or internal temperature of the support plate.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are represented in the drawings included inattachment hereto for illustrative purposes, and the scope of thisillustration is not in any way to be interpreted as limiting.

Various characteristics of the different embodiments being disclosed maybe combined to create additional embodiments, all of which areconsidered part of this illustration.

FIG. 1 shows a schematic diagram for a corner of a vehicle equipped withthe components for estimating residual torque;

FIG. 2A shows a plot of a time-based data acquisition strategy;

FIG. 2B shows a plot of a data acquisition strategy based on anactivation event;

FIGS. 3A, 3B, and 3C illustrate the first configuration of an embodimentof a residual torque estimation method that can be performed byembodiments disclosed herein;

FIGS. 4A, 4B, and 4C illustrate a second configuration of an embodimentof a residual torque estimation method that can be performed byembodiments disclosed herein;

FIGS. 5A and 5B illustrate a third configuration of an embodiment of aresidual torque estimation method that can be performed by embodimentsdisclosed herein;

FIGS. 6A and 6B illustrate a fourth configuration of an embodiment of aresidual torque estimation method that can be performed by embodimentsdisclosed herein;

FIG. 7 a plot showing a comparative example for the estimation ofresidual torque.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

The following detailed description makes reference to the attacheddrawings, which form part of this description. In the drawings, similarreference numbers typically identify similar components, unlessotherwise dictated by the context. The sequence and forms of executiondescribed in the detailed description and drawings are not intended tobe limiting. While in some drawings the components for only one cornerof the vehicle are illustrated, the characteristics of which should beunderstood as being applicable to all corners. Other embodiments may beused, and other changes may be made without deviating from the spirit orscope of the subject-matter presented herein. The aspects of thisillustration, as described generally herein and illustrated in thefigures, may be arranged, replaced, combined, separated and designed ina wide variety of different configurations, all of which are explicitlycontemplated and presented in this illustration.

According to certain embodiments, as schematically illustrated in FIG. 1, a vehicle corner 1 (e.g., a portion of a vehicle including one of thewheels of the vehicle and the corresponding brake) comprises a systemequipped with brake disc 10, friction material block 20, back supportplate 40, optional rear layer 30 between the friction material block 20and back support plate 40, and temperature sensor 100, configured andpositioned to acquire the temperature of back support plate 40.

Temperature sensor 100 can comprise a contact temperature sensorintegrated into back support plate 40, or a non-contact temperaturesensor. Additionally, temperature sensor 100 may be configured andpositioned to detect the surface temperature of back support plate 40 orthe average temperature of back support plate 40. For example,temperature sensor 100 may be positioned on the back support plate 40surface facing friction material block 20. Temperature sensor 100 may bepositioned on back support plate 40 and positioned flush with the backsupport plate 40 surface facing friction material block 20. If thesurface temperature of back support plate 40 is to be detected, however,then this surface may be a back support plate 40 surface facing towardsor away from the block of friction material 20.

Temperature sensor 100 may comprise a separate component or may besilk-screened, and, e.g., printed directly onto the metal back supportplate; different arrangements can be made by combining different typesof sensors; multiple temperature sensors may be used for distributedtemperature monitoring.

The braking element may comprise a brake pad that coordinates with abraking element represented by disc 10, as illustrated by way of examplein FIG. 1 , or another type of braking element such as a clamping jawthat coordinates with a drum.

The device for estimating residual torque can include electronic controlunit (ECU) 200, which is connected to temperature sensor 100.

The method for estimating the residual torque of a vehicle brakingelement according to this embodiment provides for temperature sensors100 to acquire the temperature detected on back support plate 40,generate the temperature signals, and transmit the temperature signalsto electronic control unit (ECU) 200.

The electronic control unit (ECU) 200 can also be connected to andreceives input signals from a number of auxiliary sensors on board thevehicle. In the illustrated embodiment, the auxiliary sensors includeone or more sensors chosen from vehicle speed sensor 50, ambienttemperature sensor 51, and brake pedal activation sensor 52.

Vehicle speed detection and the recording of ambient temperature, thetemperature for the corner of the vehicle where the braking device isoperating, can refine the algorithm's performance and resolution.

In addition, other sensors may be incorporated into the brake pad andconnected to electronic control unit (ECU) 200.

The sensors embedded in the brake pad may include one or more sensorschosen between shear strain sensor 53 and pressure force sensor 54.

According to the illustrated embodiment, the ECU 200 executes acalculation algorithm 300. For example, the calculation algorithm 300can execute to cause the ECU 200 to perform operations to implement oroversee the data collection, control and output of electronic controlunit (ECU) 200, e.g., in calculating or estimating residual torque. Forexample, the ECU 200 can comprise a computing system having one or morecomputer hardware processors (e.g., central processing units [CPUs]) andmemory storing instructions (e.g., software or firmware) which, whenexecuted by the ECU 200 implement the calculation algorithm 300.

According to certain embodiments, one or more of the signals for thevariables detected by the auxiliary sensors are used to accept thetemperature value acquired by temperature sensor 100 and are alsoconfigured, together with the acquired and accepted temperature value,into an N-dimensional array input to an N-dimensional model of thecalculation algorithm 300.

The N-dimensional model can generate a reference temperature. The ECU200 or other appropriate component can estimate residual torque bycomparing the acquired and accepted temperature to the calculatedreference temperature.

The N-dimensional calculation model can comprise an analytical orexperimental characterization of the thermal behavior of the brake.

For example, the N-dimensional calculation model can be represented bythe brake's thermal energy storage equation, where the thermal outputenergy, which equals the thermal energy lost by radiation, conduction,and convection, is equal to the incoming thermal energy generated by thefriction of contact between the braking and braked elements of thebrake.

The reference temperature, therefore, can be calculated by feeding theequation with the N-dimensional input array, which can also include aresidual pressure or residual brake-through-torque value between thebraking and braked elements, which can be assumed to have generated thereference temperature.

To estimate the residual torque with multiple identification levels, thecalculation may be repeated with different residual pressure values orresidual brake-through-torque values, which will correspond to differentreference temperature values.

FIG. 7 , for example, shows the trend over time for the acquiredtemperature T, and various values calculated for reference temperatureT_(rd1), T_(rd2), T_(rd3), and T_(rdn).

Through a calibration curve, for example, each T_(rd1), T_(rd2),T_(rd3), and T_(rdn) is associated with a corresponding residual torquevalue rd1, rd2, rd3, and rdn.

The comparison between the acquired temperature T and the calculatedreference temperature values T_(rd1), T_(rd2), T_(rd3), and T_(rdn) canbe used to estimate the residual torque value. For example, in theexample shown in FIG. 7 the comparison between the acquired temperatureT and the calculated reference temperature values T_(rd1), T_(rd2),T_(rd3), and T_(rdn) can be used to estimate the residual torque valuebetween rd2 and rd3. For example, as the acquired temperature stabilizesin a temperature range corresponding to reference temperature valuesbetween T_(rd2) and T_(rd3), a corresponding residual torque between rd2and rd3 can be determined from the calibration curve.

According to certain embodiments, each corner of the vehicle may beequipped with one or two brake pads, with or without the sensorsdescribed above.

According to certain embodiments, the residual torque calculation may beestimated by a single electronic control unit (ECU) for supervision andcontrol, or by individual electronic control units (ECU) dedicated toeach corner of the vehicle.

According to certain embodiments, the residual torque calculation may beestimated in real time.

According to certain embodiments, the acquisition and control algorithmsmay be independent of vehicle type and/or braking pad and/or drivingstyle, thanks to a self-assessment of the calibration of the signalthreshold: therefore, according to certain embodiment, no tuningoperations are necessary for the different applications.

Depending on the embodiment, the data capture may be based on twodifferent strategies: a time-based strategy, or an event-based strategy.

According to certain embodiments, the residual torque estimate, e.g.,the technique used to estimate the residual torque, is independent ofthe data acquisition strategy.

FIG. 2A shows a time-based data acquisition strategy. For example, thetime-based acquisition of the braking element temperature can be basedon a sampling frequency established over at least one time interval. Thedata acquisition can be synchronous with preset and constant acquisitionperiods, e.g., typically from 20 to 60 seconds, and preferably 30seconds, during the entire operation of the vehicle. For example, theECU 200 may execute the algorithm 300 to implement the time-based dataacquisition strategy.

The acquisition can take place independently of brake pedal activation;activation of the pedal can be recorded.

FIG. 2B illustrates a data capture strategy based on a trigger event.For example, temporal acquisition of brake element temperature can bebased on continuous sampling capture logic over at least one fixed timeinterval from the instant of acquisition determined by the triggering ofa braking event. For example, the ECU 200 may execute the algorithm 300to implement this data acquisition strategy.

Activating the brake pedal can trigger the acquisition of data within asubsequent time window, e.g., typically from 10 to 60 minutes,preferably 30 minutes.

The data capture within the time window can happen with preset andconstant acquisition periods, e.g., typically from 20 to 60 seconds,preferably 30 seconds.

Any activation of the brake pedal within an already open time window cantrigger a subsequent time window starting from the brake pedalactivation event.

A first configuration of an embodiment of the residual torque estimationsystem and method according to certain embodiments is illustrated inFIGS. 3A, 3B and 3C.

FIG. 3A schematically illustrates an example of the system.

The system includes at least one temperature sensor 100, ambienttemperature sensor 51, speed sensor 50, brake pedal activation sensor52, and electronic control unit (ECU) 200, which can provide an estimateof residual torque 500 by processing the signals with algorithm 300. Forexample, the system of FIG. 3A can comprise the system of vehicle corner1 shown in FIG. 1 .

FIG. 3B shows an example of a first logical flow of an example of theresidual torque estimation method, e.g., implemented by the algorithm300 executed on the ECU 200 of the systems of FIG. 1 or FIG. 3A.

The ambient temperature detection in the corner of the vehicle detectedby ambient temperature sensor 51 can be used for seasonal calibration ofthe temperature detected by temperature sensor 100 of back support plate40 of the brake pad. For example, ECU 200 can adjust or otherwisecalibrate the temperature detected by the temperature sensor 100 usingthe ambient temperature detected by the ambient sensor 51 to calibratefor the ambient temperature.

According to the illustrated embodiment, an initial estimate of residualtorque 500 is obtained through calculation section 310, which evaluatesthe first derivative of the detected temperature over time, and section320, which processes it based on the braking status, thereby obtainssubstantially immediate or real-time information, especially for highlevels of residual torque.

Calculation section 330 performs temperature selection under non-brakingconditions based on the data received from temperature sensor 100, ascorrected by ambient temperature sensor 51, from the data processed bycalculation section 320, as shown above, from brake pedal activationsensor signal 52, and from the speed detected by vehicle speed sensor50.

Calculation section 330 filters the temperature that is acquired andaccepted in calculation section 340 by using low-pass filters toeliminate high-frequency peaks and components.

Calculation section 330 also generates a variable flag that enablesreference temperature evaluation through calculation section 350, usingN-dimensional model 351 powered by an N-dimensional vector of organizedbrake pad temperature data detected by sensor 100, ambient temperaturedetected by sensor 51, vehicle speed detected by sensor 50 and the timedetected relative to the braking event detected by sensor 52.

N-dimensional model 351 may alternatively comprise an analytical modelderived from an analytical description of the energy exchanged betweenthe disc and the pad during braking, or an experimental model derivedfrom a set of experimental data collected during a series of dynamicenergy exchanges between disc and pad.

Calculation section 350 can calculate the reference temperature byfeeding, for example, the equation representing the thermal equilibriumof the brake with the N-dimensional input array, which also includes aresidual pressure or residual brake-through-torque value between thebraking and braked elements, which are assumed to have generated thereference temperature.

Calculation section 360 receives and compares the selected temperatureevaluation signals filtered by calculation section 340 and the referencetemperature signal from calculation section 350 and produces andprocesses a signal for residual torque estimate 500.

This signal is then compared with the signal obtained from calculationsection 320.

FIG. 3C shows a second example of a logical flow of an example of theresidual torque estimation method, e.g., implemented by the algorithm300 executed on the ECU 200 of the systems of FIG. 1 or FIG. 3A.

This second logical flow differs from the first, as described above andillustrated in FIG. 3B, due to the lack of activation of calculationsections 310 and 320. Rather, the signal for residual torque estimate500 is simply the signal obtained from calculation section 360.

FIGS. 4A, 4B, and 4C show a second configuration of certain embodimentsof a residual torque estimation system and method.

FIG. 4A schematically illustrates the system's architecturalconfiguration.

The architecture includes at least one temperature sensor 100, ambienttemperature sensor 51, brake pedal activation sensor 52, and electroniccontrol unit (ECU) 200, which provides an estimate of residual torque500 by processing signals through algorithm 300.

The architecture of the second configuration differs from the firstconfiguration shown in FIG. 3A due to the lack of speed data acquisitionfrom vehicle speed sensor 50. For example, the system of FIG. 4A cancomprise the system of vehicle corner 1 shown in FIG. 1 , but withoutthe vehicle speed sensor 50.

FIG. 4B shows an example of a first logical flow of a residual torqueestimation method, e.g., implemented by the algorithm 300 executed onthe ECU 200 of the systems of FIG. 1 or FIG. 4A.

The ambient temperature detection in the corner of the vehicle detectedby ambient temperature sensor 51 can be used for seasonal calibration ofthe temperature detected by temperature sensor 100 of back support plate40 of the brake pad. For example, ECU 200 can adjust or otherwisecalibrate the temperature detected by the temperature sensor 100 usingthe ambient temperature detected by the ambient sensor 51 to calibratefor the ambient temperature.

According to the illustrated embodiment, an initial estimate of residualtorque 500 is obtained through calculation section 310, which evaluatesthe first derivative of the detected temperature over time, and section320, which processes it based on the braking status: this obtainsimmediate information, especially for high levels of residual torque.

Calculation section 330 performs temperature selection under non-brakingconditions based on the data received from temperature sensor 100, ascorrected by ambient temperature sensor 51, from the data processed bycalculation section 320, as shown above, from brake pedal activationsensor signal 52.

Calculation section 330 filters the temperature that is acquired andaccepted in calculation section 340 by using low-pass filters toeliminate high-frequency peaks and components.

Calculation section 330 also generates a variable flag that enablesreference temperature evaluation through calculation section 350, usingN-dimensional model 351 powered by an N-dimensional vector of organizedbrake pad temperature data detected by sensor 100, ambient temperaturedetected by sensor 51, and the time detected relative to the brakingevent detected by sensor 52.

Calculation section 360 receives and compares the selected temperatureevaluation signals filtered by calculation section 340 and the referencetemperature signal from calculation section 350 and produces andprocesses a signal for residual torque estimate 500.

This signal is then compared with the signal obtained from calculationsection 320.

FIG. 4C shows a second example of a logical flow of an example of theresidual torque estimation method based on a second configuration of thepreferred embodiment, e.g., implemented by the algorithm 300 executed onthe ECU 200 of the systems of FIG. 1 or FIG. 3A.

This second logical flow differs from the first, as described above andillustrated in FIG. 4B, due to the lack of activation of calculationsections 310 and 320. Rather, the signal for residual torque estimate500 is simply the signal obtained from calculation section 360.

FIGS. 5A and 5B illustrate a third configuration of certain embodimentsof a residual torque estimation system and method.

The third configuration differs from the first configuration shown inFIG. 3A due to the lack of brake pedal activation data acquisition fromsensor 52. For example, the system of FIG. 5A can comprise the system ofvehicle corner 1 shown in FIG. 1 , but without the pedal activationsensor 52.

FIG. 5B shows an example of a first logical flow of a residual torqueestimation method, e.g., implemented by the algorithm 300 executed onthe ECU 200 of the systems of FIG. 1 or FIG. 5A.

The ambient temperature detection in the corner of the vehicle detectedby ambient temperature sensor 51 can be used for seasonal calibration ofthe temperature detected by temperature sensor 100 of back support plate40 of the brake pad. For example, ECU 200 can adjust or otherwisecalibrate the temperature detected by the temperature sensor 100 usingthe ambient temperature detected by the ambient sensor 51 to calibratefor the ambient temperature.

According to the illustrated embodiment, an initial estimate of residualtorque 500 is obtained through calculation section 310, which evaluatesthe first derivative of the detected temperature over time, and section320, which processes it based on the braking status: this obtainsimmediate information, especially for high levels of residual torque.

One variant of the embodiment does not include calculation section 310.

Calculation section 330 performs temperature selection under non-brakingconditions based on the data received from temperature sensor 100, ascorrected by ambient temperature sensor 51, from the data processed bycalculation section 320, as shown above, from the signal from vehiclespeed sensor 50.

Calculation section 330 filters the temperature that is acquired andaccepted in calculation section 340 by using low-pass filters toeliminate high-frequency peaks and components.

Calculation section 330 also generates a variable flag that enablesreference temperature evaluation through calculation section 350, usingN-dimensional model 351 powered by an N-dimensional vector of organizedbrake pad temperature data detected by sensor 100, ambient temperaturedetected by sensor 51, and vehicle speed detected by sensor 50.

Calculation section 360 receives and compares the selected temperatureevaluation signals filtered by calculation section 340 and the referencetemperature signal from calculation section 350 and produces andprocesses a signal for residual torque estimate 500.

This signal is then compared with the signal obtained from calculationsection 320.

FIGS. 6A and 6B illustrate a fourth configuration of a preferredembodiment of the residual torque estimation method.

FIG. 6A schematically illustrates the system's architecturalconfiguration.

The architecture of the fourth configuration differs from the firstconfiguration shown in FIG. 3A due to the lack of brake pedal activationdata acquisition from sensor 52 and the speed data from vehicle speedsensor 50. For example, the system of FIG. 6A can comprise the system ofvehicle corner 1 shown in FIG. 1 , but without the vehicle speed sensor50 or pedal activation sensor 52.

FIG. 6B shows an example of a logical flow of a residual torqueestimation method based on a fourth configuration of the preferredembodiment, e.g., implemented by the algorithm 300 executed on the ECU200 of the systems of FIG. 1 or FIG. 6A.

The ambient temperature detection in the corner of the vehicle detectedby ambient temperature sensor 51 can be used for seasonal calibration ofthe temperature detected by temperature sensor 100 of back support plate40 of the brake pad. For example, ECU 200 can adjust or otherwisecalibrate the temperature detected by the temperature sensor 100 usingthe ambient temperature detected by the ambient sensor 51 to calibratefor the ambient temperature.

According to the illustrated embodiment, an initial estimate of residualtorque 500 is obtained through calculation section 310, which evaluatesthe first derivative of the detected temperature over time, and section320, which processes it based on the braking status: this obtainsimmediate information, especially for high levels of residual torque.

One variant of the embodiment does not include calculation section 310.

Calculation section 330 performs temperature selection under non-brakingconditions based on the data received from temperature sensor 100, ascorrected by ambient temperature sensor 51, from the data processed bycalculation section 320, as shown above.

Calculation section 330 filters the temperature that is acquired andaccepted in calculation section 340 by using low-pass filters toeliminate high-frequency peaks and components.

Calculation section 330 also generates a variable flag that enablesreference temperature evaluation through calculation section 350, usingN-dimensional model 351 powered by an N-dimensional vector of organizedbrake pad temperature data detected by sensor 100, and ambienttemperature detected by sensor 51.

Calculation section 360 receives and compares the selected temperatureevaluation signals filtered by calculation section 340 and the referencetemperature signal from calculation section 350 and produces andprocesses a signal for residual torque estimate 500.

This signal is then compared with the signal obtained from calculationsection 320.

Other changes and variations to the method and the device for estimatingthe residual torque of a vehicle brake element are possible.

The disclosed methods and systems for estimating the residual torque ofa vehicle brake element can be subject to changes and variants whilestill falling within the scope of the inventions described herein,including equivalents.

For example, any type of appropriate materials and systems may be used.

Although certain devices, systems, and processes have been disclosed inthe context of certain example embodiments, it will be understood bythose skilled in the art that the scope of this disclosure extendsbeyond the specifically disclosed embodiments to other alternativeembodiments and/or uses of the embodiments and certain modifications andequivalents thereof. Use with any structure is expressly within thescope of this present disclosure. Various features and aspects of thedisclosed embodiments can be combined with or substituted for oneanother in order to form varying modes of the assembly. The scope ofthis disclosure should not be limited by the particular disclosedembodiments described herein.

Certain features that are described in this disclosure in the context ofseparate implementations can also be implemented in combination in asingle implementation. Conversely, various features that are describedin the context of a single implementation can also be implemented inmultiple implementations separately or in any suitable subcombination.Moreover, although features may be described above as acting in certaincombinations, one or more features from a claimed combination can, insome cases, be excised from the combination, and the combination may beclaimed as any subcombination or variation of any subcombination.

Terms of orientation used herein, such as “top,” “bottom,” “proximal,”“distal,” “longitudinal,” “lateral,” and “end” are used in the contextof the illustrated embodiment. However, the present disclosure shouldnot be limited to the illustrated orientation. Indeed, otherorientations are possible and are within the scope of this disclosure.Terms relating to circular shapes as used herein, such as diameter orradius, should be understood not to require perfect circular structures,but rather should be applied to any suitable structure with across-sectional region that can be measured from side-to-side. Termsrelating to shapes generally, such as “circular” or “cylindrical” or“semi-circular” or “semi-cylindrical” or any related or similar terms,are not required to conform strictly to the mathematical definitions ofcircles or cylinders or other structures, but can encompass structuresthat are reasonably close approximations.

Conditional language, such as “can,” “could,” “might,” or “may,” unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments include or do not include, certain features, elements,and/or steps. Thus, such conditional language is not generally intendedto imply that features, elements, and/or steps are in any way requiredfor one or more embodiments.

Conjunctive language, such as the phrase “at least one of X, Y, and Z,”unless specifically stated otherwise, is otherwise understood with thecontext as used in general to convey that an item, term, etc. may beeither X, Y, or Z. Thus, such conjunctive language is not generallyintended to imply that certain embodiments require the presence of atleast one of X, at least one of Y, and at least one of Z.

The terms “approximately,” “about,” and “substantially” as used hereinrepresent an amount close to the stated amount that still performs adesired function or achieves a desired result. For example, in someembodiments, as the context may dictate, the terms “approximately”,“about”, and “substantially” may refer to an amount that is within lessthan or equal to 10% of the stated amount. The term “generally” as usedherein represents a value, amount, or characteristic that predominantlyincludes or tends toward a particular value, amount, or characteristic.As an example, in certain embodiments, as the context may dictate, theterm “generally parallel” can refer to something that departs fromexactly parallel by less than or equal to 20 degrees.

Some embodiments have been described in connection with the accompanyingdrawings. The figures are to scale, but such scale should not belimiting, since dimensions and proportions other than what are shown arecontemplated and are within the scope of the disclosed presentdisclosure. Distances, angles, etc. are merely illustrative and do notnecessarily bear an exact relationship to actual dimensions and layoutof the devices illustrated. Components can be added, removed, and/orrearranged. Further, the disclosure herein of any particular feature,aspect, method, property, characteristic, quality, attribute, element,or the like in connection with various embodiments can be used in allother embodiments set forth herein. Additionally, it will be recognizedthat any methods described herein may be practiced using any devicesuitable for performing the recited steps.

Various illustrative embodiments of devices, systems, and methods havebeen disclosed. Although the devices, systems, and methods have beendisclosed in the context of those embodiments, this disclosure extendsbeyond the specifically disclosed embodiments to other alternativeembodiments and/or other uses of the embodiments, as well as to certainmodifications and equivalents thereof. This disclosure expresslycontemplates that various features and aspects of the disclosedembodiments can be combined with, or substituted for, one another.Accordingly, the scope of this disclosure should not be limited by theparticular disclosed embodiments described above, but should bedetermined only by a fair reading of the claims that follow as well astheir full scope of equivalents.

What is claimed is:
 1. A method for estimating a residual torque in abrake of a vehicle, the method comprising: acquiring a temperature of abraking element of the brake; determining that the brake is notactivated at an acquisition time of the acquiring of the temperature;calculating a reference temperature using an N-dimensional calculationmodel with an N-dimensional vector of input variables; and estimatingresidual torque based on at least the calculated reference temperature,wherein the N-dimensional vector of input variables includes at leastthe acquired temperature of the braking element, and wherein theN-dimensional calculation model comprises an analytical or experimentalcharacterization of thermal behavior of the brake.
 2. The method ofclaim 1 wherein the estimating comprises comparing the acquiredtemperature to the calculated reference temperature.
 3. The method ofclaim 1, wherein the N-dimensional vector of input variables furthercomprises at least a speed of the vehicle.
 4. The method of claim 1,wherein the N-dimensional vector of input variables further comprises atleast an ambient temperature.
 5. The method of claim 1, wherein theN-dimensional vector of variables further comprises at least a timedelay between a time of the temperature acquisition and a last time inwhich the brake was activated.
 6. The method of claim 1, wherein thebraking element comprises a braking disc, a block of friction material,and a support plate supporting the block of friction material, whereinthe temperature of the braking element is acquired by at least onetemperature sensor configured and positioned to detect the temperatureof the support plate.
 7. The method of claim 1, wherein said acquiringthe temperature of the braking element comprises sampling according totemporal acquisition logic based on a sampling frequency for at leastone preset time interval.
 8. The method of claim 1, wherein saidacquiring the temperature of the braking element comprises continuouslysampling for at least one preset time interval starting at a timedetermined by an event.
 9. The method of claim 1, wherein thedetermining whether the brake is activated at the acquisition time ofthe acquiring of the temperature value comprises using at least one ofvehicle speed, temperature of the braking element, temporal variation ofthe temperature of the braking element, or brake pedal status.
 10. Themethod of claim 1, wherein the estimating of the residual torque isadditionally based on a change in brake temperature over time.
 11. Asystem for estimating residual braking torque of a braking element of avehicle brake, the system comprising: a braking element comprising ablock of friction material and a support plate supporting the block offriction; at least one temperature sensor configured and positioned todetect the temperature of the braking element; a computing devicecomprising connected to the temperature sensor, the computing deviceprogrammed to: acquire a temperature associated with the braking elementfrom the temperature sensor; determine that the brake is not activatedat an acquisition time at which the temperature is acquired; calculate areference temperature using an N-dimensional calculation model with anN-dimensional vector of input variables, wherein the calculation isbased on at least the acquired temperature of the braking element as aninput to said N-dimensional calculation model; and estimate a residualtorque based on at least the calculated reference temperature.
 12. Thesystem of claim 11, wherein the estimation of the residual torque isbased on a comparison of the acquired temperature to the calculatedreference temperature.
 13. The system of claim 11, wherein theN-dimensional calculation model represents an analytical or experimentalcharacterization of a thermal behavior of the brake.
 14. The system ofclaim 11, wherein the temperature sensor is a contact temperature sensorintegrated into the support plate.
 15. The system of claim 11, whereinthe temperature sensor is a non-contact temperature sensor.
 16. Thesystem of claim 11, wherein the temperature sensor is configured andpositioned to detect a surface or internal temperature of the supportplate.
 17. The system of claim 11, wherein the computing device isprogrammed to acquire the temperature associated with the brakingelement by sampling according to temporal acquisition logic based on asampling frequency for at least one preset time interval.
 18. The systemof claim 11, wherein the computing device is programmed to acquire thetemperature of the braking element by continuously sampling for at leastone preset time interval starting at a time determined by an event. 19.The system of claim 11, wherein the computing device is programmed todetermine whether the brake is activated at the acquisition time usingat least one of vehicle speed, temperature of the braking element,temporal variation of the temperature of the braking element, or brakepedal status.
 20. The system of claim 11, wherein the computing deviceis programmed to estimate the residual torque by comparing the acquiredtemperature to the calculated reference temperature and based on achange in brake temperature over time.